Optical control of hybrid and monolithic microwave circuits, such as switches, attenuators, phase shifters and mixers, has been described in several articles. Examples of these articles include: Paolella et al, "Optical Gain Control of a GaAS MMIC Distributed Amplifier," Microwave and Optical Technology Letters, Vol. 1, No. 1, March, 1988; Jemison et al, "Optical Control of a Digital Phase Shifter," 1990 IEEE International Microwave Symposium, May, 1990, Dallas, Tex.; and Paolella et al, " Optically Controlled GaAs MMIC Switch Using a GaAs MESFET as an Optical Detector," 1990 MTT-S Symposium Digest, May 1990.
For many of the applications described in these articles, such as optically controlling the gain, phase and/or switching of the microcircuit requires detection and amplification of the optical signals and therefore, additional devices are needed to accomplish these tasks. Known prior art devices have used GaAs MESFETs as optical detectors with additional amplification stages to provide control of gain, phase and switching of microwave circuits. Examples of such devices are described in U.S. Pat. No. 4,859,965, entitled, "Optical Gain Control of GaAs MMIC Distributed Amplifier," issued to Paolella et al on Aug. 22, 1989; and U.S. Pat. No. 5,086,281, entitled, "Optical Control Circuit for a MMIC," issued to Paolella on Feb. 4, 1992.
Although gain, phase and switching of microwave circuits and mixing of two optical signals to generate a microwave signal (see Fetterman et al, "Control of Millimeter Wave Devices by Optical Mixing," Microwave and Optical Technology Letters, Vol. 1, No. 1, pp. 34-39, March 1988) have been achieved, to date, a method has not been proposed to integrate the mixing of an RF modulated optical signal with a microwave signal in a fully monolithic device. The present invention addresses this need.